EV charger not resuming charging

What you are saying here would be truth if that would be the case on all the vehicles. And it is not like that. Unfortunately, there are lots of exceptions in the design of the charging mechanism. Some vehicles are disabling charging when you open the door. Is that normal? Is the EVCS fault?
There is a standard that we followed.
If you want to return the EVCS, I can help you with that if necessary, no worries!